This invention relates to an assembly with articulated arms for moving a door of a piece of furniture by means of a roto-translatory motion, between a closing position, in which said door lies essentially on a vertical plane, with abutment with respect to the sides of said piece of furniture, and an opening position, wherein said door is cantilevered, corresponding to the top of the piece of furniture or an overlying shelf. The invention further relates to a piece of furniture.
In the furniture industry, furniture is normally made of parallelepiped formats with, as is known, two vertical parallel sides, a top, a base and an optional rear wall, defining an internal compartment where objects, food, clothing and so on can be stored.
The front opening through which said internal compartment is accessed is selectively closed by means of one or more doors, movable between a closing position, in which access to the compartment is prevented, and an opening position, in which the interior contents can be accessed.
The passage between said closing position and said opening position can be carried out in different ways: in fact, the doors can be, for example, hinged on one side of the piece of furniture in such a way that the passage from one position to another essentially takes place by rotation around a vertical axis, thus a considerable space is required and the user's lateral movement is hindered.
To overcome this drawback, sliding doors have been proposed, in which the passage from one position to another takes place by lateral or vertical sliding; however, access to a part of the interior compartment of the piece of furniture is difficult or impossible.
Recently, in particular, regarding hanging furniture for example for kitchens, but also living rooms and bathrooms, the market is aiming at opening/closing systems where the door in an opening position is “cantilevered” from the body of the piece of furniture corresponding to the cover of the piece of furniture or possibly on the top shelf in the case of furniture with more spaces; this solution is highly appreciated as it is more ergonomic and allows for easy lateral movement by users even when the door is in the opening position.
In particular, the opening position can be achieved by ensuring door rotation of at least 90° from the closing position, so that this essentially lies on the same plane defined by the cover of the piece of furniture; However, in order to ensure a greater accessibility to the interior compartment, it is preferable that the door rotates at an angle greater than 90° from the closing position, so that this, in the opening position, is placed along a slanted plane with respect to the plane defined by the top, and preferably above it.
In order to meet this condition, the passage from the closing position to the opening position of the door must essentially take place according to a consistent trajectory in a roto-translatory motion, i.e. a combined movement in which the door contextually makes a translation, moving away from the piece of furniture and a rotation around an essentially horizontal axis; obviously this trajectory must be traced back by the door in the passage between the opening position and the closing position. This allows the trajectory of the door not to interfere, during the passage between the opening position and closing position, with any other doors, arranged in a coplanar position to the one to be moved and adjacent thereto.
Moreover, since the door in the opening position is essentially “cantilevered” from the body of the piece of furniture, for safety reasons, means must be provided that keep it in this position, preventing it, due to the action of its own weight, from uncontrollably returning to the closing position.
There are different types of devices that enable this movement to be activated. For example, systems are known that use gas pistons or springs hinged at one end to the inner side of the piece of furniture and with opposite end to the associated door, designed so that the weight of the door can be lifted and the closing movement counteracted. In such systems, the trajectory of the door is driven by variable pivot hinges attached to the top edge of the door and to the cover of the piece of furniture.
However, such systems have a drawback because numerous elements must be used and (many) holes made to attach them to the piece of furniture, both in the sides and on its top. Moreover, in particular in the case of gas pistons, because the size of the door and its weight may vary, many different types of pistons with variable force must be prepared and kept in stock.
Another known type of device for handling a door uses mechanisms with articulated arms that can be attached to the inner surface of the sides of the piece of furniture and can perform the same desired roto-translatory movement and keep the door in an opening position without needing to use hinges in the cover of the piece of furniture.
Lifting mechanisms for doors of this type are described for example in documents WO 2012/059173 and US 2013/0333291, both of which essentially include the same elements, organized in a different way; in particular, they comprise an elastic mechanism, such as a spring, that is rotatably coupled with a first end at the side of the piece of furniture around a first axis, e.g. a first pin, and associated at the opposite end with a rigid first arm, rotating around a second axis, e.g. a second pin, also attached to the side of the piece of furniture. This first rigid arm is in turn operationally connected to said door by means of numerous varied articulated elements between them, some of which are rotatably coupled around stationary rotational axes.
Therefore, all these mechanisms require at least three axes/pins attached to the side of the piece of furniture to enable movement of the door.
A cover casing, generally made of polymeric material, is then attached to the side of the piece of furniture to hold and protect the assembly of the door, also avoiding that users can accidently injure themselves by trapping their fingers inside the assembly when it is moving.
Although these mechanisms normally work satisfactorily, some drawbacks have been found: first of all, they are rather complex and bulky, detracting useful space from the inside of the piece of furniture and harming its aesthetic appearance.
Moreover, despite the presence of the cover casing, there is a possibility that users can also be injured; in fact, when the door is in the opening position, and therefore the assembly is in an extended configuration, the inner cavity of the cover casing is essentially accessible through a side opening required for the movement of the articulated arms.
Finally, if necessary, such mechanisms can be servo-assisted, attaching linear actuators operated by electric motors to them, which makes them even more bulky.